Red Bull team boss Christian Horner has fuelled speculation that Renault's future in formula one is far from secure.

Red Bull team boss Christian Horner has fuelled speculation that Renault's future in formula one is far from secure.

The Briton has admitted that he is on the market for a new customer engine, because Red Bull's current contract with its French supplier is due to expire.

"We need to know if Renault is staying in formula one," Horner is quoted as saying by Germany's Sport Bild. "We don't know that for sure at the moment."

Renault is set to lose the title backing of the struggling Dutch bank ING at the end of the year, but boss Flavio Briatore insists the situation is no worse for Renault amid the economic crisis than it is for any of its rivals.

And he told Spain's Sport newspaper: "I've been to the president of Renault in Paris and he confirmed to me that F1 is a priority for the group."